Vacuum packaging film is used for vacuum sealing of perishable items. Due to the film's versatility in producing vacuum sealed packages of various sizes, its popularity has increased in recent years. As a result, continuous product improvement is required on the part of manufacturers in order to stay competitive. One such improvement has been applying patterns to vacuum packaging bags.
For vacuum packaging bags with smooth inner surfaces (i.e., inner surfaces that do not have a pattern), the bag surfaces sometimes stick together when air is evacuated from the bag during vacuum packaging. This may result in air pockets within the seal and degraded seal integrity. In response to this problem, manufacturers may imprint or emboss a pattern onto vacuum packaging film used to form the vacuum packaging bags. The pattern helps prevent vacuum packaging bag surfaces from sticking together during vacuum packaging by forming channels along the grooves of an imprinted pattern—or forming channels between raised portions of an embossed pattern—when the surfaces of the bag are face to face. The pattern may be applied to one or both of the inner surfaces of the vacuum packaging bag.
While imprinting or embossing a pattern onto vacuum packaging film is generally desirable, imprinting or embossing a pattern introduces new problems. For example, embossed patterns may be less durable than smooth surfaces. In general, the farther an embossed pattern sticks out from the surface of vacuum packaging film, the less durable the film becomes. Moreover, thicker embossing—or deeper grooves—typically consumes more material and may be harder to apply to or form into the film. Thicker embossing—or deeper grooves—also typically results in thicker vacuum packaging film, which makes the film heavier and less compact so it takes up more space in storage. Furthermore, if the surface of a vacuum packaging film has a high concentration of raised areas, there will be fewer channels formed when evacuating a vacuum packaging bag made of the film. Since there are fewer channels, even if relatively few channels become blocked gas may be trapped and air pockets formed, resulting in degraded seal integrity.
Accordingly, what is needed is a vacuum packaging film with an improved embossing pattern to reduce embossing thickness, to reduce the concentration of raised areas on vacuum packaging film, or to increase the number of channels formed when the vacuum packaging film is used in a vacuum packaging application.